In the design and construction of sprinkler systems, it is common practice to mount the individual sprinkler head in a so-called "recessed" mode. In this construction, the sprinkler head is located above an aperture in the ceiling and does not extend below the ceiling; a cover plate is provided which is usually arranged to fall away from the ceiling and from the sprinkler head at a given temperature in order to expose the sprinkler to the hot gases from a fire. In the past, these cover plates have been mounted for the support of the cover plate on a tubular extension which, after the sprinkler is installed, is attached to a similar tubular portion surrounding the sprinkler. Since the location of the sprinkler can vary by considerable amounts, due to the water distribution pipe locations above the ceiling, it has always been difficult to place the cover in position properly, so that it is not spaced from the surface of the ceiling. Furthermore, a bayonet lock was used to join the two tubular parts and this made it difficult for the installer to make a good connection. Also, such equipment is quite expensive, since all the parts are made of stamped metal and held together by a low-temperature alloy. These and other difficulties experienced with the prior art devices have been obviated in a novel manner by the present invention.
It is, therefore, an outstanding object of the invention to provide a sprinkler assembly in which a recessed sprinkler head has an improved appearance.
Another object of this invention is the provision of a sprinkler assembly including a casing and cover plate which are easy to apply by the sprinkler installer.
A further object of the present invention is the provision of a sprinkler assembly including a cover plate which drops away at a substantially low temperature to expose the sprinkler head.
It is another object of the instant invention to provide a sprinkler asembly which is simple in construction, which is inexpensive to manufacture, and which is capable of a long life of useful service with a minimum of maintenance.
With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.